The pet treat industry produces dry pet treat, semi-moist pet treat, and moist pet treat. The foods in each of these categories have different shelf lives based upon the amount of moisture they contain. The foods in each of these categories have different levels of fresh meat content.
Numerous processes exist for producing food products for pets. Many of these contain a low percentage of fresh meat or have a very short shelf life.
U.S. Pat. No. 4,127,678, entitled Caseinate Replacement in Semi-Moist Pet Foods, to Burkwall, Jr. describes a semi-moist pet food having the appearance and texture of meat, which formerly required sodium caseinate to achieve the meat-like texture and appearance after processing, now includes a pregelatinized or modified amylaceous material, a non-caseinate protein source, and a substantially neutral chelating agent in a combination to replace at least part of the casein salt in the semi-moist pet food to still achieve the meat-like texture and appearance after processing. Burkwall uses additional starch to partially replace the caseinate salts. Burkwall's preferred range of meat content is 15 to 35 percent. The moisture content of Burkwall's invention is about 15 percent to about 50 percent by weight. Burkwall's invention contains fat in the amount of about 0 to 12 percent by weight of the final product. This patent describes the use of an extruder in making the semi-moist pet food.
U.S. Pat. No. 4,332,832, entitled Animal Food and Method, to Buckley et al. describes a rehydratable dry animal food being prepared by a mix of comminuted, heat-treated meaty materials, fat and pregelatinized starch carbohydrate binder, forming the mix into pieces and drying the pieces to form a permeable solid pieces which rehydrate to a paste-like material of heterogeneous texture. This mix preferably contains bone fragments which lend a desirable flaky texture to the rehydrated product. The pregelatinized starch carbohydrate binder may be pregelatinized potato powder or cereal products in which the starch content is in a pregelatinized form or other starch containing products in which the starch component has been pregelatinized. Mixes contain 70 to 80 percent meaty materials, 10 percent fat and 10 to 20 percent binder. The pieces are extruded under low pressure or extrusion-expanded to give an open texture. The moisture content of the final dried product is below 15%.
U.S. Pat. No. 5,552,176, entitled Pet Food Premix Preparation, to Marino describes a pet food premix product which contains about 40 to 70 percent meat and the balance of at least one farinaceous and/or plant proteinaceous carrier substrate. Marino provides a process by which meat can be dehydrated and starch can be gelatinized, then incorporated into an extruded dry or moist food at levels from 5 percent to 50 percent of a total formulation ration. The premix, when incorporated into an extruded pet food product, will increase its operational performance while delivering nutrients and palatability to the pet food product. The final premix product contains less than about 10 percent moisture. The final premix product contains about 8 to 30 percent fat by weight.
U.S. Pat. No. 3,992,353, entitled Shelf Stable, High Moisture, Filled Food Product, to Bernotavicz, describes a shelf stable, high moisture, filled food product which has meat containing filling with a major portion thereof enclosed by cooked expanded cereal. The meat containing filling has a moisture content of at least about 50 percent by weight and a water activity, A.sub.w, of at least about 0.09 and comprises cooked proteinaceous meaty materials acidified with an edible, non-toxic acid and a certain amount of antimycotic. The product is prepared by cooking a proteinaceous meaty material, mixing it with an edible, non-toxic acid and a certain amount of antimycotic, then extruding under puffing conditions a hot cooked cereal dough through a first die and simultaneously extruding the stable filling through a second die, in the same direction and without cooling, and subdividing the extrudate into food shaped pieces followed by drying the food shaped pieces to decrease the moisture content thereof. The filling containing meat has a moisture content of about 50 percent. The product includes about 2 to 4 percent fat. The meat portions and the cereal portions are cooked in a pressure cooker. They are not cooked in the extruder.
U.S. Pat. No. 5,654,028, entitled Low Calorie Meat Products, to Christensen et al. describes a low calorie meat product comprising a mixture comprising comminuted lean meat and a vegetable fat replacement ingredient comprising dietary fiber and starch. The focus of this patent is producing a low fat meat product which may contain 20 to 95 percent meat by weight. The fat contain is at most 15 percent by weight. This low fat meat product may be used as a pet food.
U.S. Pat. No. 4,579,741, entitled Fabricated Seafood, to Hanson et al. describes fabricated seafood, such as analogue shrimp meats, and their methods of preparation. A fish paste is provided which comprises about 60 to 95 percent surimi, 0 to 5 percent starch, 0 to 25 percent water and 0 to 4 percent vegetable or marine oil. The paste is blended without aeration and kept at less than 10.degree. C. The paste is extruded as a rope to a first heating zone to heat set the exterior to form a skin. The rope is then fed to an in-line static mixture to texturize the still soft rope core. The textured rope is then heated again to firm the texturized core. The rope is then shaped into pieces of predetermined size and shape and then coagulated by heat application thereto. The fabricated seafood so prepared are characterized by the "bite," an aligned or braided fibrous interior, and the skin of real shrimp.
U.S. Pat. No. 5,676,986, entitled Food Products Made From Protease Enzyme Containing Fish, Methods of Making Same, and Methods to Inactive Protease Enzyme In Fish, to Choudhury describes a method for proteolytic degradation of fish muscle having protease enzyme which includes distributing the enzyme uniformly throughout the fish muscle and drying the fish muscle thereafter. Choudhury describes a method of making a food product and includes reducing hydrolyzed fish muscle to a powdered form, and then mixing the fish muscle in powder form with a starchy and/or proteinaceous material to form a mixture which is subsequently subjected to high temperature extrusion processing to form a desired food product. Choudhury describes processes for tenderizing or causing substantial or complete proteolytic degradation of animal muscle by applying onto the animal muscle, protease enzyme obtained from fish having the enzyme present therein. Also disclosed is the resulting food products resulting from these processes. This patent describes using 5 to 60 percent fish meat.
U.S. Pat. No. 5,290,584, entitled Method of Preparing a Snack Food Jerky Product, to Ray describes a method of preparing and producing a nutritious, low calorie, low cholesterol, shelf-stable, expanded snack food product for humans and pets. The process involves using a proteinaceous material, such as raw comminuted meats or mechanically separated meats. The proteinaceous material may be meats which are frozen or chilled. This meat is further comminuted to relatively small particle size to provide optimum dispersion of the meat products with the farinaceous (starch) component of the mixture. This blend containing the raw, frozen or chilled meat products, is mixed with pregelatinized flour and is then subjected to elevated temperatures and shear pressure as it moves through the high-temperature, short-time, screw-type extruder. Flavorings, colorings, spices, and the like, may be blended with the ingredients or may be topically applied to the extrudate prior to packaging and after cutting to desired lengths. The moisture content of the final product is less than 20 percent by weight. The fat content of the final product is less than 8 percent by weight. The starch content prior to extrusion is approximately 80 to 90 percent by weight. The protein content after extrusion is approximately 10 to 12 percent.